Nature and the time course of seizures associated with surgical removal of the pineal gland from parathyroidectomized rats

About 80% of male rats that are parathyroidectomized at 23 days of age and are pinealectomized a week later exhibit intermittent seizures and frequently death. Characteristically, the seizures are violent and death is probably a result of asphyxiation. The peak incidence of seizures in these rats occurs within 8 hr after pinealectomy and approximately 50% of the animals die within 48 hr of the operation. Chlordiazepoxide (18-20 mg/kg), diazepam (18-20 mg/kg) or chlorpromazine (20 mg/kg), given as single subcutaneous doses at the time of pinealectomy, delayed the onset of the seizures. Haloperidol (20 mg/kg) had a modest suppressive effect on the seizure activity. Diphenylhydantoin (20 mg/kg) did not affect the percentage of rats that convulsed, the onset of the seizures, the frequency of the seizures, or the 48 hr mortality.